Chapter 41
Which of the following are considered essential nutrients: (1) certain carbohydrates, (2) certain fatty acids, (3) certain amino acids, and/or (4) cholesterol?
2 and 3
Which of the following statements regarding protein digestion is true?
Active pepsin is formed in the lumen of the stomach, where it helps to break down proteins.
Which of the following animals rely on symbiotic relationships to obtain nutrients?
All the listed responses are correct.
Which of the following statements about nutrition and digestion is true?
During absorption, small molecules such as amino acids and simple sugars are absorbed.
True
Ingestion is the act of eating.
_______ are needed in the diet as components of teeth and bone, as parts of certain enzymes, for normal muscle and never function, and for water balance.
Minerals
How is the stomach lining protected from the strongly acidic pH of its contents?
Mucous cells secrete a protective lubricant into the stomach.
Pepsin is an enzyme produced in the stomach that attacks proteins to break them down into smaller peptide molecules. Which of the following statements about this enzyme is true?
Pepsin will cease to function in the small intestine as basic secretions from the pancreas neutralize the pH.
How would you expect the digestive system of a hawk to compare with that of a seed-eating sparrow?
The sparrow's digestive system would be longer.
What relation do indigestible plant fibers, prokaryotes, and vitamins have with the digestive system?
They are the contents of the large intestine.
B vitamins should be consumed daily, but A vitamins can be consumed more sporadically. Why is this true?
Vitamin A can be stored in body fat, but B vitamins are not stored by the body.
Which of the following might make the most effective anti-ulcer medication?
a chemical that kills bacteria in the stomach
Which of the following processes, structures or conditions are properly matched.
acid chyme backflow ... heartburn
Leptin, an appetite regulator, is produced in _______ and at high levels can lead to _______.
adipose tissue ... suppressed appetite
The lymphatic vessels in the villi absorb and transport
chylomicrons
In general, B vitamins function in your body as _______.
coenzymes
Acid chyme _______.
contains food and gastric juice and moves through the pyloric sphincter
The liver and pancreas add their secretions to the partially digested food produced stomach, in the _______, of the small intestine.
duodenum
Four classes of essential nutrients
essential amino acids, essential fatty acids, vitamins, and minerals
Researchers provided radioactively labeled food to a dog and traces the movement of absorbed molecules. Which type of molecule moved along a path different from all the others?
fats
Several days after a long holiday weekend including much overeating, you try to cut back on your calories. The first day that you reduce your calories intake to below the levels that you need, your body will respond by using which of the following.
glycogen from the liver
Which of the following animals has a gastrovascular cavity with a single opening?
hydra
Every time you eat a cookie or candy bar, your blood sugar increases. This triggers an increase in blood levels of the hormone ________.
insulin
Type 1 diabetes mellitus _______.
is an autoimmune disease in which the immune system attacks beta cells in the pancreas
Which sequence below correctly describes the maintenance of blood glucose levels?
low blood sugar, pancreatic alpha cells stimulated, glucagon released, breakdown of glycogen in target cells.
An insufficient supply of chemical energy in the diet or a shortage of one or more essential nutrients results in which of the following?
malnutrition
Where does absorption take place in the small intestine?
microvilli
Chemical digestion of carbohydrates begins in the _______ with the action of _______.
mouth ... salivary amylase
Which food items are typical of an herbivorous diet?
nuts, leaves, berries
Overnourishment is a direct cause of _______.
obesity
Animals need two types of organic precursors from their food, _______, to serve as the raw materials for the synthesis of larger organic molecules.
organic carbon and organic nitrogen
Which of the following is acquired outside of an animal's diet?
oxygen
The natural antacid that protects the intestines against stomach acid is produced by the _______.
pancreas
In vertebrates, food is moved along the length of the digestive system by _______.
peristalsis
Despite long days grazing on tall grasses, several of the cattle released into a new pasture have oddly shaped or broken legs often lay down. These cattle might be suffering from _______.
phosphorus deficiency
The tongue does all of the following EXCEPT _______.
secrete saliva
Which of the following is an adaptation to a carnivorous diet?
sharp, pointed teeth
In humans, most nutrient molecules are absorbed by the _______.
small intestine
Most digestive enzymes function in the _______.
small intestine
A breakfast cereal advertises that ti contains essential vitamins and minerals. In this context, the word essential means _______.
that the nutrients must be supplied in the diet and cannot be made in the body
During some types of antibiotic treatments, patients often experience diarrhea because _______.
the bacterial flora of the the large intestine that normally break down undigested organic material are killed by the antibiotics
Gallstone surgery sometimes required that the gallbladder be removed. Patients are then advised to avoid ingesting large amounts of fat because _______.
the gallbladder stores large quantities of bile, which is used to emulsify fats
The lungs consist of many small air sacs and blood vessels, which greatly increase surface area and improve the transfer of substances through their walls. The structures in the digestive system most similar in function to these air sacs and capillaries are the _______.
villi and microvilli
Symbiotic bacteria living in our large intestines provide us with _______.
vitamins
Fat-soluble vitamins
vitamins A, D, E, and K